Deriving tooth condition information for populating digital dental charts

ABSTRACT

Disclosed are methods and digital tools for deriving tooth condition information for a patient’s teeth, for populating a digital dental chart with derived tooth condition information, and for generating an electronic data record containing such information.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Pat. Application No.17/128,273, which was filed on Dec. 21, 2020, which is a continuation ofU.S. Pat. Application No. 15/780,519, which was filed on May 31, 2018,which is a national stage application of PCT/EP2016/079749, which wasfiled on Dec. 5, 2016, and which claims the priority of Danish PatentApplication No. PA 201570803, which was filed on Dec. 4, 2015. Thesubject matter of U.S. Serial No. 17/128,273; U.S. Serial No.15/780,519; PCT/EP2016/079749; and Danish Patent Application No. PA201570803 are incorporated herein by reference.

TECHNICAL FIELD

This invention generally relates to methods, systems, computer programproducts and digital environments for deriving tooth conditioninformation for a patient’s teeth and for populating dental charts withtooth condition information. More particularly, the invention relates tomethods, systems, computer program products and digital environmentswhere individual teeth are identified from a digital 3D representationof the patient’s teeth and the derived tooth condition information iscorrelated with the individual teeth.

BACKGROUND

Dental practice management systems frequently use dental charts forstoring information regarding a patient’s dental situation. Such dentalcharts are known as an efficient tool for visualizing informationregarding the condition of a patient’s teeth.

Standardized dental charts often has regions representing the surfacesof the individual teeth normally found in a patient’s mouth. In suchcharts there is usually one specific region for each specific toothsurface. Different colors, geometrical figures or other visualrepresentations are used to visualize e.g. caries, dental restorativework, root problems etc. on the dental chart.

Digital dental charts are also know e.g. from US8,416,984 wherein amethod for generating a digital dental chart from a scan of thepatient’s teeth and populating the generated digital dental chart withtooth condition information is disclosed.

In prior art systems derived tooth condition information is manuallyannotated/mapped/transferred onto the standardized/schematicrepresentation of the patient’s teeth used in the dental practicemanagement systems. This is both time consuming and is prone to humanerror risking that e.g. the information is annotated to the wrong partof the tooth or even to the wrong tooth.

It remains to provide method and digital tools for deriving toothcondition information for a patient’s teeth and for populating a digitaldental chart with such information which have fewer manual steps andaccordingly are less prone to human errors. The digital tools can e.g.be a computer system, a computer program product, or a digitalenvironment.

SUMMARY

Disclosed is a method for deriving tooth condition information for apatient’s teeth,

-   wherein the method comprises:-   obtaining a digital 3D representation of the patient’s teeth;-   identifying the individual teeth in the digital 3D representation;-   segmenting the individual teeth from the digital 3D representation;-   obtaining diagnostic data for one or more of the teeth;-   deriving tooth condition information from the diagnostic data; and-   correlating the derived tooth condition information with the    individual teeth.

The segmentation and identification of the teeth in the digital 3Drepresentation provides that it is known which portions of the digital3D representation relate to the patient’s individual teeth. Thearrangement of the individual teeth in the digital 3D representation isthus also known.

When the spatial correlation between the diagnostic data and the digital3D representation also is known the segmentation and identification ofthe teeth in the digital 3D representation provides that the diagnosticdata can be correlated with the individual teeth. i.e. it can bedetermined for which tooth the diagnostic data are recorded from. Thespatial correlation between the diagnostic data and the digital 3Drepresentation is known e.g. when the diagnostic data are comprised inthe digital 3D representation or when the spatial correlation isdetermined by aligning parts of the diagnostic data with correspondingparts of the digital 3D representation.

When the diagnostic data are spatially correlated with the digital 3Drepresentation the spatial correlation between the individual teeth ofthe digital 3D representation and the tooth condition informationderived from the diagnostic data will then often also be known.Accordingly, the segmentation and identification of the teeth providesthat the derived tooth information can be linked to the patient’sindividual teeth, i.e. it can be determined for which tooth a giventooth condition information is derived for.

In some embodiments, correlating the derived tooth information with theidentified and segmented teeth comprises determining the location of thetooth condition on the tooth. The tooth condition information can thenbe mapped onto the correct position on the region of the dental chart.

As explained above, tooth condition information can be visualized in adigital dental chart. Accordingly herein is also disclosed a method forpopulating a digital dental chart with tooth condition information,wherein the method comprises:

-   deriving tooth condition information for one or more of the teeth by    using the method, system, computer program product and/or digital    environment according to any of the embodiments;-   obtaining a digital dental chart comprising regions representing    surfaces of the patient’s teeth;-   correlating the individual teeth with the corresponding regions of    the digital dental chart; and-   adding a representation of the derived tooth condition information    to the corresponding region or regions of the digital dental chart.

I.e. the method, the computer program product, the digital environment,and the system may be configured for populating a digital dental chartwith tooth condition information for the individual teeth of a patient.

A standardized digital dental chart often has regions representing thesurfaces of the individual teeth normally found in a patient’s mouth. Insuch charts there is usually one specific region for each specific toothsurface. The segmentation and identification of the individual teeth ina digital 3D representation provides that the teeth portions of thedigital 3D representation can be linked to the corresponding regions ofthe digital dental chart. The knowledge of the spatial correlationbetween the digital 3D representation and the diagnostic data providesthat it is known which tooth the derived tooth condition informationrelates to. The representation of the derived tooth conditioninformation can thus be added to the correct region of the dental chartrepresenting the tooth surface for which the tooth condition informationwas derived for.

When the derived tooth condition information is added to a digitaldental chart the digital dental chart expresses the current condition ofleast one tooth with respect to at least one dental condition such asthe presence of e.g. caries, cracks in the tooth surface or dentalrestorations.

In some cases the digital dental chart is populated and visualized in adental practice management system. Herein is also disclosed a method forgenerating an electronic data record configured for use in a dentalpractice management system, where the electronic data record comprisestooth condition information for the individual teeth of a patient,wherein the method comprises:

-   deriving tooth condition information for one or more of the teeth by    using the method, system, computer program product and/or digital    environment according to any of the embodiments; and-   storing the tooth condition information for the identified teeth in    the electronic data record.

Disclosed is a method comprising:

-   obtaining a digital 3D representation of a patient’s teeth;-   obtaining diagnostic data for one or more of the teeth;-   identifying individual teeth of the digital 3D representation;-   deriving tooth condition information from the diagnostic data, and-   correlating the derived tooth information with the identified    individual teeth.

Disclosed is a digital environment configured for assisting an operatorin performing the steps of the disclosed method.

Disclosed is a computer program product comprising computer readableinstructions which when executed by an electronic data processing deviceprovides a digital environment for performing the steps of the disclosedmethod.

Disclosed is a system comprising:

-   an electronic data processing device; and-   a non-transitory computer readable medium encoded with the disclosed    computer program product.

In some embodiments, the method, the computer program product, thedigital environment, or the system is for deriving tooth conditioninformation for the individual teeth of a patient.

In some embodiments, the method, the computer program product, thedigital environment, or the system is for populating a digital dentalchart with tooth condition information for the individual teeth of apatient. The method then comprises a step of populating the digitaldental chart with the derived tooth condition information.

In some embodiments, the method, the computer program product, thedigital environment, or the system is for generating an electronic datarecord configured for use in a dental practice management system, wherethe electronic data record comprises tooth condition information for theindividual teeth of a patient. The method then comprises storing thederived tooth condition information for the identified teeth in theelectronic data record.

In some embodiments, the method comprises segmenting individual teethfrom the digital 3D representation.

The segmentation and identification of the individual teeth in a digital3D representation provides that the teeth portions of the digital 3Drepresentation can be linked to the corresponding regions of the digitaldental chart. This provides for a more efficient and faster procedurewhich is less prone to human errors.

Disclosed is a digital environment comprising:

-   a digital loading tool for loading a digital 3D representation of    the patient’s teeth and diagnostic data for one or more of the teeth    into the digital environment;-   a digital work space adapted for visualizing the digital 3D    representation and/or the diagnostic data;-   a digital identification tool for identifying individual teeth of    the digital 3D representation;-   a digital deriving tool for deriving tooth condition information    from the diagnostic data, and-   a digital correlating tool for correlating the derived tooth    information with the identified individual teeth.

In some embodiments, the digital environment comprises a digitalsegmentation tool for segmenting the individual teeth from the digital3D representation.

In some embodiments, the digital environment comprises a digitalpopulating tool for populating a digital dental chart with the derivedtooth condition information.

Disclosed is a digital environment comprising a digital work space,where the digital environment is configured for:

-   obtaining a digital 3D representation of the patient’s teeth and    displaying the digital 3D representation in the digital work space;-   obtaining diagnostic data for one or more of the teeth; and-   assisting an operator in performing the steps of a method    comprising:    -   identifying individual teeth in the digital 3D representation;    -   segmenting the individual teeth from the digital 3D        representation;    -   deriving tooth condition information from the diagnostic data;        and    -   correlating the derived tooth information with the individual        teeth.

Disclosed is a user interface configured for deriving tooth conditioninformation for a patient’s teeth, wherein the user interface isconfigured for:

-   obtaining a digital 3D representation of the patient’s teeth;-   identifying individual teeth in the digital 3D representation;-   segmenting the individual teeth from the digital 3D representation;-   obtaining diagnostic data for one or more of the teeth;-   deriving tooth condition information from the diagnostic data; and-   correlating the derived tooth information with the individual teeth.

Disclosed is a system for deriving tooth condition information for apatient’s teeth, wherein the system is configured for obtaining adigital 3D representation of the patient’s teeth and diagnostic data forone or more of the teeth, and where the system comprises anon-transitory computer readable medium encoded with a computer programproduct comprising computer readable instructions for:

-   identifying individual teeth in the digital 3D representation;-   segmenting the individual teeth from the digital 3D representation;-   deriving tooth condition information from the diagnostic data; and-   correlating the derived tooth information with the individual teeth.    Disclosed is a system for deriving tooth condition information for a    patient’s teeth, the system comprising:-   an electronic data processing device; and-   a non-transitory computer readable medium encoded with a computer    program product comprising computer readable instructions which when    executed by the electronic data processing device provides a digital    environment for deriving tooth condition information for the teeth    by a method comprising:    -   i. obtaining a digital 3D representation of the patient’s teeth;    -   ii. obtaining diagnostic data for one or more of the teeth;    -   iii. identifying individual teeth in the digital 3D        representation;    -   iv. segmenting the individual teeth from the digital 3D        representation;    -   v. deriving tooth condition information from the diagnostic        data; and    -   vi. correlating the derived tooth information with the        individual teeth. Disclosed is a user interface configured for        populating a digital dental chart with tooth condition        information for a patient’s teeth, wherein the user interface is        configured for:-   obtaining a digital 3D representation of the patient’s teeth;-   identifying individual teeth in the digital 3D representation;-   segmenting the individual teeth from the digital 3D representation;-   obtaining diagnostic data for one or more of the teeth;-   deriving tooth condition information from the diagnostic data;-   correlating the derived tooth information with the individual teeth;-   obtaining a digital dental chart comprising regions representing    tooth surfaces;-   correlating the individual teeth with the corresponding regions of    the digital dental chart; and-   adding a representation of the derived tooth condition information    to the corresponding regions of the digital dental chart.

The digital 3D representation comprises shape data expressing thetopography of 10 one or more of the patient’s teeth. The segmentationand identification of the teeth is preferably based at least partly onthese shape data. In some cases the digital 3D representation alsocomprises shape data for the patient’s gingiva. Gingiva conditioninformation can then be derived either independently or as part of thetooth condition information.

The digital 3D representation can be obtained by intra-oral scanning, byscanning an impression of the patient’s teeth or a physical model of theteeth formed using such an impression.

Some scanning technologies are capable of measuring both the shape ofthe tooth surface as well as internal structures inside the tooth. Thisis e.g. the case for X-ray based scanners, such as Cone Beam ComputedTomography scanners, and optical coherence tomography scanners. Suchscanners can provide a digital 3D representation which contains bothshape data for the topography of the tooth as well as data relating tothe internal structure and sub-surface damages in the tooth and thepresence of caries and dental restorations.

In some embodiments, at least part of the diagnostic data are comprisedin the digital 3D representation. One advantage of this embodiment isthat the diagnostic data and the tooth portions segmented from thedigital 3D representation already are correlated. When the diagnosticdata are comprised in the digital 3D representation they are oftenaligned with the shape data expressing the topography of the segmentedteeth. For example tooth shade data can be recorded simultaneously withthe shape data such that in the obtained digital 3D representation theshade data and shape data for the teeth are precisely correlated.

There is hence no need for an additional step of aligning the diagnosticdata with the shape data of the digital 3D representation to provide ordetermine the spatial correlation between the two. In this caseobtaining the digital 3D representation and obtaining the diagnosticdata is performed as one step, i.e. the digital 3D representation andthe diagnostic data are obtained in the same step of the method.

The diagnostic data can also be the shape data of the digital 3Drepresentation, such as when the tooth condition relates to e.g. toothwear or gingiva retraction where the condition can be determined fromanalysis of the shape data.

In some embodiments the digital 3D representation comprises shape data,color or shade data, and fluorescence data. Such digital 3Drepresentation may comprise data in the form of (x, y, z, color data,fluorescence intensity data). Here (x,y,z) represents the coordinates inspace for a point on the tooth surface, the color data and fluorescenceintensity data provide information regarding the tooth color andfluorescence, respectively, measured from the (x,y,z) point of the toothsurface. The color data can e.g. be provided in (RGB) coordinates. Thedigital 3D representation then comprises data in the form of (x, y, z,R, G, B, fluorescence intensity).

In some embodiments, the diagnostic data and the digital 3Drepresentation of the patient’s teeth are recorded using differentdevices such that the diagnostic data initially are not part of thedigital 3D representation. This may e.g. be the case when the digital 3Drepresentation is recorded using an intra-oral scanner providing asurface scan of the teeth while the diagnostic data are X-ray data, suchas data recorded using a CBCT scanner.

In some embodiments, at least part of the diagnostic data are comprisedin a diagnostic data set obtained in addition to the digital 3Drepresentation of the patient’s teeth. At least part of the toothcondition information can then be derived from this diagnostic data set.Such a diagnostic data set may be used e.g. when diagnostic data areextracted from scanners which does not record sufficiently precise ordetailed shape data for the tooth surface, or when the diagnostic dataare provided in the form of 2D images. Other examples of diagnostic datathat may be obtaining from a diagnostic data set are CBCT data,separately obtained fluorescence data and IR data.

In such cases it can be advantageous to determine the spatialcorrelation between the digital 3D representations and the diagnosticdata, i.e. the spatial correlation between the digital 3D representationand the diagnostic data of the diagnostic data set. The correlation cane.g. be expressed as a transformation bringing the digital 3Drepresentation and the diagnostic data into a common coordinate systemwith the correct relative arrangement. Determining this correlation mayprovide that the spatial relationship between tooth and/or gingivacondition information derived from the diagnostic data and the shapedata of the digital 3D representation also is determined. This isadvantageous e.g. when using a computer program product for mapping thederived tooth and/or gingiva condition information onto the digitaldental chart.

The spatial correlation may e.g. be determined based on aligningportions of the digital 3D representation and the diagnostic datarelating to the same surface either based on fiducial markers, landmarkidentification or aligning the surfaces using e.g. an Iterative ClosestPoint algorithm.

In some embodiments the digital 3D representation is formed from a firstdigital 3D representation comprising shape data for the teeth and asecond digital 3D representation comprising the diagnostic data. Whenthe spatial correlation between the first and second digital 3Drepresentations has been determined a digital 3D representation can beformed that contains both the shape data of the first digital 3Drepresentation and the diagnostic data of the second digital 3Drepresentation.

The correlation between the derived tooth condition information and theidentified individual teeth of the digital 3D representation can bebased on the determined spatial relationship between the digital 3Drepresentation and the diagnostic data set.

The segmentation of the teeth from the digital 3D representationpreferably isolate the portions of the digital 3D representationcorresponding to the individual teeth from the remaining part of thedigital 3D representation. I.e. the data of the digital 3Drepresentation relating to the individual teeth are isolated from eachother and from other parts of the digital 3D representation such asparts relating to the patient’s gingiva.

The segmentation step can be performed before or after the teeth havebeen identified. If performed before, the identification can be based onthe segmented teeth. If performed after, the identification thesegmentation can be based on the knowledge of which tooth the given partof the digital 3D representation relates to.

The segmentation can be realized both with and without user interaction.If the digital 3D representation is visualized in a display such as acomputer screen an operator can use a pointing too, such as a computermouse to mark the boundaries of the individual teeth on the digital 3Drepresentation. The segmentation of the teeth from the digital 3Drepresentation can then be based on the marked boundaries. Computerbased algorithms can also be applied to identify e.g. the transitionfrom tooth surface to gingiva and the boundary of a tooth at its contactwith neighbor teeth such that the segmentation can be made without orwith limited user interaction.

When the diagnostic data comprises texture data, such as color data, thesegmentation can also be based at least partly on the diagnostic data.For example the boundary of the tooth at the gingiva can be detectedfrom the difference in the color of teeth and gingiva.

In some embodiments, the tooth condition information for a tooth isderived from variations in the diagnostic data over the segmented toothportion of the digital 3D representation. When the diagnostic data arecomprised in the digital 3D representation, the diagnostic data areinherently linked to the shape data for the teeth. In some cases, suchas when the tooth condition is the presence of caries in a given part ofa tooth derived from a local variation in the fluorescence emitted fromthat tooth, the derived tooth condition information is alreadycorrelated with the tooth portion of the digital 3D representation.

In some embodiments, the diagnostic data represents an intensity of asignal recorded from the teeth and variations in the intensity over thetooth surfaces indicates the presence of e.g. caries or an existingdental filling. The presence of a tooth condition can both be indicatedby an increase or a decrease in the intensity of the signal at thelocation of the condition.

When sound teeth are illuminated by light with wavelength around 405 nmthe teeth emits fluorescence with a broad emission at 500 nm that istypical of natural enamel. In caries infected areas of teeth additionalpeaks are often seen at 635 nm and 680 nm due to emission from porphyrincompounds in oral bacteria. I.e. the presence of caries can be detectedby measuring whether the fluorescence signal at 635 nm and 680 nmrecorded from a particular area of a tooth is stronger than from other(healthy) parts of the tooth. The increased strength of the fluorescentsignal then provide a direct representation of caries in a tooth.

A decrease in the natural fluorescence emitted at 500 nm from teethilluminated by light at wavelength of e.g. 405 nm can be caused byscattering in a region with caries. Detecting a lower fluorescencesignal (around 500 nm) can thus be an indication of the presence ofcaries in that area of the tooth.

The diagnostic data may express a spatial distribution of the toothcondition. This may be the case when the diagnostic data arefluorescence data showing that a tooth is attacked by caries at aspecific region of the tooth, e.g. the in a particular region on theocclusal surface.

In some embodiments, the tooth condition information comprises thelocation of the condition on the tooth. The derived information thusdescribes both the condition and which part of the tooth is affected bythe condition. In the case of caries the tooth condition information maythen comprise information describing that caries is present in the toothand that it e.g. is located on the occlusal surface of the tooth.

When the digital 3D representation and/or the diagnostic data comprisesdata for the patient’s gingiva the method may comprise derivinginformation relating to the condition of the gingiva, such as its shape,color, spatial relationship to the teeth, or the depth of the gingivalpockets. Monitoring the gingiva shape and its spatial relationship tothe teeth over time provides a means for detecting gingiva retractionand deepening of the gingival pockets.

In some embodiments, identifying the individual teeth comprisescomparing the segmented teeth with digital template teeth of a toothdatabase. This is possible since different teeth have different shapes(e.g. an anterior tooth does not have the same shape as a posteriortooth). Whether a given molar tooth belongs to the left or right side ofthe patient’s mouth can e.g. be determined from the location of thecorresponding data in the digital 3D representation of the patient’steeth.

When the teeth have been identified the result of the identification canbe visualized in a user interface allowing an operator to confirm thatthe identification is correct.

In some embodiments, the teeth are manually identified by an operatorusing e.g. a pointing tool on a visualization of the set of teeth in auser interface. The dentist or operator often sees a visualization ofthe teeth during a procedure and manually identifying the individualteeth can be made using a pointing tool in connection with avisualization of the teeth on a display.

In some embodiments, the identification of the teeth in the obtaineddigital 3D representation is based on an identification made for apreviously obtained digital 3D representation of the patient’s teeth.This previously obtained digital 3D representation may have beenanalyzed while applying the method during a previous visit at thedentist. The previous analysis provides knowledge of the actual shape ofthis particular patient’s teeth such that the teeth portions of thedigital 3D representation obtained during the current visit can becompared with the actual shape. Such comparison is potentially easierand more precise than a comparison with template teeth of a tooth database.

In some embodiments, the shapes of the identified teeth are stored inthe electronic data record. This provides the advantage that theidentification of the teeth during a subsequent use of the method, suchas during a subsequent visit at the dentist, can be based on the actualshape of the patient’s set of teeth. Such identification is potentiallymuch faster and requires less computational force compared to when e.g.the teeth are identified based on a comparison with standard teethshapes.

In some embodiments, the diagnostic data comprises data selected fromthe group consisting of texture data, such as tooth color data or toothshade data, fluorescence data, Infrared data, X-ray data, opticalcoherence tomography data, ultrasound data, laser speckle images, ordata representing the occlusal contacts between antagonist teeth. Inprinciple any kind of data suitable for diagnostic purposes and forexpressing the condition of the teeth can be used.

In the context of the present disclosure the phrase “Fluorescence data”refers to data acquired by a fluorescence measurement detecting afluorescent signal emitted from the tooth in response to illumination bya probe beam comprising light at wavelengths capable of exitingfluorescent material of or at the teeth. The excitation may e.g. useblue or green light depending on which material is to be excited.

In the context of the present disclosure the phrase “Infrared data”refers to data acquired by an infrared measurement, e.g. by an infraredscanner, where the transmission or variations in the transmission oflight at Infrared wavelengths through the analyzed tooth or teeth aredetected. Variations in the intensity of the infrared light transmittedthrough a tooth can e.g. be due to dental fillings, cracks in the toothsurface or caries.

Occlusal contacts with antagonist teeth can e.g. be determined using avirtual articulator mimicking the relative movement of the teeth duringthe bite. The occlusal contacts can also be recorded using articulatingpaper which leaves color markings on the teeth. If the digital 3Drepresentation of the teeth is acquired using an intra-oral scanningrecording both teeth shape and color the contact points can be derivedfrom the digital 3D representation. The derived occlusal contact canthen be mapped onto the digital dental chart.

The X-ray data can e.g. be in the form of cone-beam computed tomographyimage or 2D X-ray images.

In some embodiments the derived tooth condition information relates toinformation selected from the group consisting of tooth shade, toothwear, caries, presence of cariogenic bacteria, presence of fillings fromprevious dental work, acid erosion damages, bruxism induced damages,tooth arrangement, malocclusion or gingiva retraction.

The tooth arrangement can be derived as part of an orthodontic treatmentwherein the changes in the arrangement of the patient’s teeth ismonitored. Storing the tooth condition information, i.e. the tootharrangement, derived for the patient’s teeth during the treatment thenprovides a strong tool for the orthodontist in visualizing the progressand for confirming that the treatment progresses as planned.

Damages caused by acid erosion or bruxism can be detected from laserspeckle images providing information on the microstructure of theenamel. Such damages can also be detected to monitor the change in theshape of the patient’s teeth over time.

The presence of cariogenic bacteria or fractures on a microstructurescale can be indicators of developing caries in the tooth.

Information can be derived for several teeth and with respect to severaldifferent dental conditions.

In some embodiments, the operator will manually annotate the derivedtooth condition information onto the digital dental chart.

In some embodiments, the method comprises obtaining a digital dentalchart comprising regions representing surfaces of the patient’s teethand adding a representation of the derived tooth condition informationto the region or regions of the digital dental chart corresponding tothe tooth or teeth for which the dental condition information isderived.

In some embodiments the digital dental chart comprises regionsrepresenting tooth surfaces, i.e. for each of the teeth normally foundin a patient’s set of teeth the digital dental chart has one or moreregions representing the surfaces of the tooth. For the anterior teeththe digital dental chart may comprise a region representing the labialsurface and a region representing the lingual surface of each tooth. Foreach of the posterior teeth the digital dental chart may comprise aregion representing the buccal surface, a region representing thelingual surface and a region representing the occlusal surface. E.g. ifcaries is detected in one of the canines a representation showing thedentist that carries is present in that tooth is added to the regions ofthe dental chart representing this tooth.

In some embodiments, the digital dental chart comprises a 2D dentalchart with regions representing the different surfaces of the teeth. Thediagnostic data or the derived tooth condition information for asegmented tooth may then be projected onto the corresponding region inthe digital dental chart. The region can e.g. represent a buccal/labial,an occlusal or a lingual surface of the teeth in the digital dentalchart.

The digital dental chart may be in the form of a standard dental chartwherein the regions representing the different teeth are generalized.

In some embodiments, the regions are formed based on the correspondingsurfaces of the teeth such that the digital dental chart is apersonalized dental chart wherein the regions of the dental chart areshaped and/or colored and/or arranged according to the actual situationin the patient’s mouth.

In some embodiments, adding the derived tooth condition information tothe digital dental chart comprises mapping a representation of thederived information onto the digital dental chart. The tooth conditioninformation is then visualized at the correct region in the digitaldental chart.

In some embodiments, the diagnostic data are mapped onto the digitaldental chart. For example shade data or fluorescence data can be mappedonto the regions of the digital dental chart such that the digitaldental chart shows the tooth surface representations with the diagnosticdata projected onto the regions.

In some embodiments, the diagnostic data comprises texture data and arepresentation of the texture data is projected onto the regions of thedigital dental chart representing the surfaces of the teeth.

Derived information regarding the condition of the patient’s gingiva mayalso be added to the digital dental chart. The gingiva conditioninformation may be mapped onto the digital dental chart.

Tooth condition information derived manually, such as from of separateimages X-ray images, may be manually annotated on the digital dentalchart.

In some embodiments, the tooth condition information is represented onthe digital dental chart using a color code, geometrical or textsymbols, a vector map, or one or more arrows. Such arrows can e.g. beused to indicate a movement since last update of the chart when thedigital dental chart is used to monitor an orthodontic treatment.Populating the digital dental chart may thus comprise projecting asymbol for the information onto the corresponding region of the digitaldental chart.

In some embodiments, the digital dental chart is formed at least partlyfrom the digital 3D representation.

This provides an advantage when the diagnostic data are comprised in thedigital 3D representation of the teeth since the correlation between thedigital dental chart and the digital 3D representation established orused when forming the digital dental chart also can be used for themapping of the derived tooth condition information or the diagnosticdata onto the digital dental chart.

In some embodiments, the digital dental chart is obtained by loading adental chart template into a computer system configured for executingthe instructions of a computer program product that provides the stepsof the disclosed methods.

Disclosed is a method for deriving tooth condition information for apatient’s teeth, wherein the method comprises:

-   loading a digital 3D representation of the patient’s teeth and    diagnostic data for one or more of the teeth into an electronic data    processing device, and-   executing a computer program product using said electronic data    processing device, where the computer program product comprises    computer readable instructions for:    -   identifying the individual teeth in the digital 3D        representation;    -   segmenting the individual teeth from the digital 3D        representation;    -   deriving tooth condition information from the diagnostic data;        and    -   correlating the derived tooth information with the identified        individual teeth.

Disclosed is a method for deriving tooth condition information for apatient’s teeth, wherein the method comprises:

-   loading a digital 3D representation of the patient’s teeth and    diagnostic data for-   one or more of the teeth into a digital environment; and-   in the digital environment performing the steps of:    -   identifying the individual teeth in the digital 3D        representation;    -   segmenting the individual teeth from the digital 3D        representation;    -   deriving tooth condition information from the diagnostic data;        and    -   correlating the derived tooth information with the identified        individual teeth.

Disclosed is a computer program product comprising computer readableinstructions for:

-   obtaining a digital 3D representation of the patient’s teeth;-   obtaining diagnostic data for one or more of the teeth; and-   deriving tooth condition information for the patient’s teeth by a    procedure comprising:    -   identifying the individual teeth in the digital 3D        representation;    -   segmenting the individual teeth from the digital 3D        representation;    -   deriving tooth condition information from the diagnostic data;        and    -   correlating the derived tooth information with the identified        individual teeth.

Disclosed is a computer program product comprising computer readableinstructions which when executed by an electronic data processing deviceprovides a digital environment for deriving tooth condition informationfor a patient’s teeth by a method comprising:

-   loading a digital 3D representation of the patient’s teeth into the    digital environment;-   identifying the individual teeth in the digital 3D representation;-   segmenting the individual teeth from the digital 3D representation;-   loading diagnostic data for one or more of the teeth into the    digital environment;-   deriving tooth condition information from the diagnostic data; and-   correlating the derived tooth information with the identified    individual teeth.

In some embodiments, the computer readable instructions perform one ormore of the steps of the method when executed, such as the steps ofidentifying, segmenting, deriving, and correlating.

Disclosed is a computer program product comprising computer readableinstructions for providing a virtual environment comprising a userinterface, where the virtual environment is configured for:

-   obtaining a digital 3D representation of the patient’s teeth and    displaying the digital 3D representation in the user interface;-   obtaining diagnostic data for one or more of the teeth; and-   assisting a user in deriving tooth condition information for the    patient’s teeth by a procedure comprising:    -   i. identifying the individual teeth in the digital 3D        representation;    -   ii. segmenting the individual teeth from the digital 3D        representation;    -   iii. deriving tooth condition information from the diagnostic        data; and    -   iv. correlating the derived tooth information with the        individual identified teeth.

In some embodiments, the virtual environment is configured fordisplaying the diagnostic data or a digital diagnostic data filecontaining the diagnostic data in the user interface. Disclosed is anon-transitory computer readable medium encoded with the disclosedcomputer program product.

In some embodiments, the electronic data record is configured for beingloaded into a dental practice management system.

The dental practice management system can then preferably read the toothcondition information from the electronic data record such that thedental practice management system e.g. can visualize the derived toothcondition information in a digital dental chart. The dental practicemanagement system may also be configured for comparing the toothcondition information and/or gingiva condition information of the loadedelectronic data record with information derived from diagnostic dataobtained at an earlier time. The digital dental chart can e.g. bevisualized in a user interface of the dental practice management system.

In some embodiments the user interface is configured for togglingbetween displaying the digital dental chart and displaying the digital3D representation of the teeth. The digital dental chart can e.g.comprise a 2D dental chart with regions visualizing the visible surfacesof the patient’s teeth where the derived information is mapped ontothese regions, while the digital 3D representation shows both shape ande.g. shade or fluorescence data obtained from the teeth.

This provides the advantage that the operator, such as a dentist, easilycan change between the different views and thereby have easy access tothe different knowledge provided by the different views.

The toggling between the different views can e.g. be provided when avirtual push button is pressed or activated in any other suitable way.

In some embodiments, the user interface is configured for togglingbetween displaying the digital dental chart with the derived toothinformation visualized in the corresponding regions and displaying thedigital dental chart with the derived information hidden.

This can be advantageous when the texture data, such as color or toothshade, is visualized on the digital dental chart. Toggling then allowsone view to be with the digital 3D representation with e.g. shade dataclearly visible without interfering with tooth condition information andanother view providing the tooth condition information.

In some embodiments, one view of the dental chart comprises the digital3D representation with only shape data and with tooth conditioninformation mapped onto the regions of the digital 3D representation.

This provides the advantage that the tooth condition information is seenon a digital 3D visualization of the teeth but without any texture datainterfering with the tooth condition information.

In some embodiments the digital 3D representation is recorded while abite wing is arranged at the patient’s teeth and the method comprisesregistering a digital model of the bite wing with the digital 3Drepresentation to derive the information of the bite wing relative tothe patient’s teeth.

The disclosed embodiment can be used both for adding tooth and gingivacondition information to a clean digital dental chart or for updating anexisting digital dental chart for the patient. I.e. the obtained digitaldental chart may be a clean template digital dental chart or apreviously populated digital dental chart already comprising diagnosticdata or tooth condition information for the patient’s teeth such thatgenerating the digital dental chart provides an updated digital dentalchart for the patient’s teeth.

Disclosed is a method for deriving tooth condition information for apatient’s teeth, wherein the method comprises:

-   obtaining a digital representation of the patient’s teeth;-   identifying the individual teeth in the digital representation;-   segmenting the individual teeth from the digital representation;-   obtaining diagnostic data for one or more of the teeth;-   deriving tooth condition information from the diagnostic data; and-   correlating the derived tooth information with the individual teeth.

In some embodiments, the digital representation of the teeth comprises adigital 2D representation or a digital 3D representation of the teeth.

Furthermore, the disclosure relates to a computer program productcomprising computer readable instructions for causing a data processingsystem to perform the method according to any of the embodiments whensaid computer readable instructions are executed on the data processingsystem, and a computer program product, comprising a computer-readablemedium having stored there on the computer readable instructions.Disclosed is a non-transitory computer readable medium storing thereon acomputer program, where said computer program is configured for causingcomputer-assisted deriving of tooth condition information for apatient’s teeth, wherein the deriving comprises identifying thepatient’s individual teeth in and segmenting the individual teeth froman obtained digital 3D representation of the patient’s teeth, andderiving tooth condition information for the individual teeth fromdiagnostic data obtained for one or more of the teeth.

The present invention relates to different aspects including the method,computer program products, systems, digital environments, and userinterfaces described 20 above and in the following, and correspondingmethods, computer program products, systems, and/or user interfaces,each yielding one or more of the benefits and advantages described inconnection with the first mentioned aspect, and each having one or moreembodiments corresponding to the embodiments described in connectionwith the first mentioned aspect and/or disclosed in the appended claims.

EMBODIMENTS

1. A method for populating a digital dental chart with tooth conditioninformation, wherein the method comprises:

-   deriving tooth condition information for one or more of the teeth by    using-   the method according to any one of the disclosed embodiments;-   obtaining a digital dental chart comprising regions representing    tooth surfaces;-   correlating the identified and segmented teeth with the    corresponding regions of the digital dental chart; and-   adding a representation of the derived tooth condition information    to the corresponding region or regions of the digital dental chart.

2 The method according to embodiment 1, wherein adding the derived toothcondition information to the digital dental chart comprises mapping therepresentation of the derived information onto the digital dental chart.

3. The method according to embodiment 1 or 2, wherein the toothcondition information is represented on the digital dental chart using acolor code, geometrical or text symbols, a vector map, or one or morearrows .

4. The method according to any of embodiments 1 to 3, wherein thedigital dental chart is formed at least partly from the digital 3Drepresentation.

5. The method according to any of embodiments 1 to 4, wherein thediagnostic data comprises texture data and a representation of thetexture data is projected onto the regions of the digital dental chartrepresenting the surfaces of the teeth.

6. The method according to embodiment 5, wherein the digital dentalchart comprises a 2D dental chart with regions representing thedifferent surfaces of the teeth and where the diagnostic data or thederived tooth condition information for a segmented tooth are projectedonto the corresponding region in the digital dental chart.

7. A method for generating an electronic data record configured for usein a dental practice management system, where the electronic data recordcomprises tooth condition information for the individual teeth of apatient, wherein the method comprises:

-   deriving tooth condition information for one or more of the teeth by    using the method of any one of the disclosed embodiments; and-   storing the tooth condition information for the identified teeth in    the electronic data record.

8. The method according to embodiment 7, wherein the shape data for thesegmented and the identified teeth are stored in the electronic datarecord.

9. The method according to embodiment 7 or 8, wherein the electronicdata record is configured for being loaded into a dental practicemanagement system.

10. A virtual environment configured for deriving tooth conditioninformation for a patient’s teeth, wherein the virtual environment isconfigured for:

-   obtaining a digital 3D representation of the patient’s teeth;-   identifying the individual teeth in the digital 3D representation;-   segmenting the individual teeth from the digital 3D representation;-   obtaining diagnostic data for one or more of the teeth;-   deriving tooth condition information from the diagnostic data; and-   correlating the derived tooth information with the individual teeth.

11. The virtual environment according to embodiment 19, wherein thetooth condition information is visualized on the digital dental chartusing a color code, geometrical or text symbols, a vector map, or one ormore arrows.

12. The virtual environment according to embodiment 20, wherein thevirtual environment is configured for toggling between displaying thedigital dental chart and displaying the digital 3D representation.

13. The virtual environment according to embodiment 20 or 21, whereinthe virtual environment is configured for toggling between displayingthe digital dental chart with the derived tooth information visualizedin the corresponding regions and displaying the digital dental chartwith the derived information hidden.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or additional objects, features and advantages of thepresent invention, will be further elucidated by the followingillustrative and non-limiting detailed description of embodiments of thepresent invention, with reference to the appended drawings, wherein:

FIG. 1 shows a dental chart used for recording tooth conditioninformation.

FIG. 2 shows a schematic of a flowchart.

FIGS. 3A, 3B, 3C and 3D illustrate steps of an embodiment.

FIG. 4 shows a system according to an embodiment.

FIG. 5 shows user interface system according to an embodiment.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanyingfigures, which show by way of illustration how the invention may bepracticed.

FIG. 1 shows a dental chart used for recording tooth conditioninformation. This dental chart 100 has standardized regions representingthe surfaces and the root of each tooth. For example the dental chart100 has regions 101, 102 and 103 representing the lingual, occlusal andbuccal surfaces, respectively, of tooth #32 while region 104 representsthe roots of that tooth.

The regions representing the tooth surfaces can be shaped to resemblethe teeth even more than seen in FIG. 1 or be more schematic. Mostdental charts has regions for all teeth usually found in the human mouthas also seen in the chart illustrated in FIG. 1 . Different symbols canbe used for visualizing the tooth condition information derived for thepatient’s teeth. In the dental chart of FIG. 1 there is among otherthings a composite filling in tooth 11 symbolized by a ring filled withdots 105.

Such dental charts have been known for decades in paper form and arealso part of many digital dental practice management systems where adigital dental chart is used.

FIG. 2 shows a schematic of a flowchart 210 for an embodiment.

In step 211 the digital 3D representation of the patient’s teeth withthe shape data describing the topography of the teeth is obtained. Thedigital 3D representation can be recorded using an intra-oral scanner,such as the TRIOS intra-oral scanner produced by 3shape A/S or byscanning an impression of the teeth or a physical model if the teethmanufactured from the impression.

The digital 3D representation is loaded into a data processing systemhaving a non-transitory computer readable medium encoded with a computerprogram product having computer readable instructions for identifyingand segmenting the individual teeth from the remaining parts of thedigital 3D representation (step 212). These operations provide thatdigital models of the individual teeth are obtained and given thecorresponding teeth number.

The tooth identification can be handled by tooth recognition algorithmsexecuted by the data processing system where e.g. the digital models ofthe individual teeth are compared with standardized teeth CAD models forthe different types of teeth normally found in person’s mouth. Theidentification can also be based on symmetry across the patient’s medialplane which provides a reference for the teeth numbering.

In step 213 the diagnostic data for the teeth is obtained. Thediagnostic data can e.g. be color data, shade data, fluorescence data,Infrared data, Cone beam computed tomography (CBCT) data, and occlusalcontact data.

FIG. 2 illustrates obtaining of the digital 3D representation 211 andthe diagnostic data 213 as separate steps. However this is notnecessarily the case since some diagnostic data may be obtained as partof the digital 3D representation, i.e. such that actions of steps 211and 213 are performed in one single step. If for example an intra-oralscanner is configured for recording color, such as the TRIOS 3intra-oral scanner, diagnostic data in the form of color or shade datacan be recorded simultaneously with the shape data of the digital 3Drepresentation. The obtained digital 3D representation then comprisesboth shape data and diagnostic data for the teeth.

The diagnostic data are also loaded into the data processing system andin step 214 tooth condition information is derived from the obtaineddiagnostic data. The analysis for deriving the tooth conditioninformation depends on the character of the diagnostic data and theinformation that is being derived.

In case the diagnostic data are fluorescence data the derivedinformation can relate e.g. to the presence of caries or cariogenicbacteria in a part of the patient’s tooth or the presence of fillings ordental restorations. Cariogenic bacteria produce porphyrin compoundswhich emit a fluorescent signal at wavelengths above 600 nm in responseto excitation by a probe light at wavelength of 405 nm. If the porphyrincompounds are present on part of the tooth surface there will be astronger fluorescent signal from that part of the tooth surface and thecariogenic bacteria are detected from the local increase in theintensity of the fluorescence.

The fluorescence data can be recorded as part of the digital 3Drepresentation using a scanner which detects the shape data based onprobe light reflected from the teeth surfaces and simultaneously recordsthe longer wavelength fluorescent signal. This can be realized if theprobe light is provided by a blue LED or laser emitting light at awavelength of 405 nm and the detector of the scanner applies a Bayerfilter to distinguish between the reflected light and the fluorescentsignal. In that case the fluorescence data can be recordedsimultaneously with the reflected light and the recorded digital 3Drepresentation comprises both shape data and the fluorescence data.

The analysis of the diagnostic data can be made by an operator based ona visualization of the diagnostic data e.g. in a user interface forconfigured for assisting the operator in performing steps of the method.For instance diagnostic data in the form of Infrared data for thepatient’s teeth can be presented in the user interface and the operatorcan identify tooth sections scattering the infrared light as e.g. cariesor fractures in the enamel of the tooth.

The analysis can also be performed by a computer program product havinginstructions for detecting variations in e.g. the intensity of thediagnostic data over the tooth. For example the scattering of infraredlight by a fracture in the enamel will cause a locally lower intensityof the transmitted infrared light. The presence and position of such alocal intensity minimum can be derived by the computer program productwhereby the tooth condition information is derived from the analyzeddiagnostic data.

In step 215 the digital dental chart is obtained. This can be obtainedfrom a database of a dental practice management system and either be aclean template for the recording of tooth condition information at apatient’s first visit at the clinic or t can be a digital dental chartalready populated with such information at one or more previous visitsat the clinic. The digital dental chart can have standardizedrepresentations of the patient’s teeth as the one illustrated in FIG. 1.

In step 216 the obtained digital dental chart is populated with thederived tooth condition information. When the information has beenderived from diagnostic data which are spatially correlated with thedigital 3D representation, i.e. the spatial correlation of thediagnostic data and the shape data of the digital 3D representation isknown, the derived information can immediately be projected onto thecorresponding regions of the digital dental chart. If this spatialcorrelation is not established it is also possible for the operator tomanually annotate the derived information on the digital dental charte.g. using a computer mouse to indicate where on a tooth region of thedental chart the tooth condition information should be added. If gingivacondition information, such as presence of inflammation or pocket depth,has been derived from the diagnostic data this information can also beadded to the digital dental chart.

Steps 211 to 214 alone relates a method for deriving tooth conditioninformation while steps 211 to 216 relates to a method for deriving thetooth condition information and populating a digital dental chart withthe derived information.

The steps can be performed by a system having a non-transitory computerreadable medium capable of receiving and storing the digital 3Drepresentation of the patient’s teeth, the diagnostic data for one ormore of the teeth, and the digital dental chart. A computer programproduct is also stored on the medium where the computer program producthas instructions for deriving the tooth condition information and forpopulating the digital dental chart with the derived tooth conditioninformation. The graphical representation of the populated digitaldental chart can be displayed on a display unit of the system. Such asystem described in relation to FIG. 4 .

FIGS. 3A, 3B, 3C and 3D illustrate steps for deriving tooth conditioninformation and populating a digital dental chart with the derivedinformation.

FIG. 3A shows a schematic of an obtained digital 3D representation 320.The digital 3D representation can be visualized in a digital work spacepresented to the operator on a display such as a computer screen. Thedigital 3D representation 320 has shape data for the surfaces of part ofthe gingiva 321 and the six anterior teeth of the patient’s upper jaw,i.e. teeth #6 to #11 in the Universal tooth numbering system. Inaddition to the shape data expressing the topography of the teeth thedigital 3D representation 320 also provides diagnostic data in the formof fluorescence data. The fluorescence data has significantly strongerintensities in two sections 322 on the patient’s maxillary centralincisor 324 and maxillary lateral incisor 325. The fluorescence data cane.g. be from fluorescence emitted at wavelengths above 600 nm fromporphyrin compounds when these are excited by light at 405 nm. Asdescribed above porphyrin compounds indicate that cariogenic bacteriaare present.

The digital 3D representation can be obtained by an intra-oral scannerusing a blue LED to illuminate the patient’s teeth. The topography ofthe teeth can be derived from the blue light reflected from the teethsurface while tooth condition information is derived from the red lightemitted by fluorescent materials in the infected regions 322 in responseto the blue light. This provides that the fluorescence data, i.e. thediagnostic data, are obtained simultaneously with the shape data andthat the 25 fluorescence data are part of the digital 3D representationand according are spatially correlated with the shape data for theteeth.

FIG. 3B shows the obtained digital 3D representation 320 with themaxillary central incisor segmented from the digital 3D representation.The segmented portion forms a digital model 327 of the maxillary centralincisor (tooth #8) shown as a dotted line in the figure. Thesegmentation of the teeth from the digital 3D representation involves adetection of the boundaries of the surfaces for each tooth. The boundaryat the gingiva can be detected based on the shape data of the digital 3Drepresentation or on color data of the digital 3D representation. Thesegmentation can be performed by a computer program product havinginstructions configured for detecting the boundaries in the digital 3Drepresentation or by an operator marking the boundaries on the digital3D representation. The boundaries detected by the computer algorithm canalso be visualized in a digital work space such that the operator canverify that the detected boundaries are correct. The individual teethare identified using a computer program product configured for makingthe identification from the digital 3D representation. This can berealized based on an analysis of the shape of the segmented teeth and/orby a comparison with templates teeth describing standard shapes andrelative sizes of the teeth. If the digital 3D representation has shapedata for the central incisors these can be detected based on theirsymmetry and the remaining teeth identified based on their naturalposition relative to the central incisors. In FIG. 3B the segmentedtooth is identified as tooth #8 using the Universal tooth numberingsystem. Instead of using a computer program product the operator canmanually identify each tooth using e.g. a pointing tool in connectionwith the digital work space.

When the fluorescence data are obtained as part of the digital 3Drepresentation the spatial correlation between the fluorescence data andthe shape data is known. If the analysis of the fluorescence dataconcludes that the fluorescent signal recorded from some sections of theteeth, such as sections 322 at the incisal edges of the maxillarycentral incisor 324 and maxillary lateral incisor 325, is significantlystronger than the fluorescent signal from other parts of the teeth it isconcluded that there is a risk that cariogenic bacteria are present inthese sections. I.e. based on the fluorescence data the system or theoperator derives the tooth condition information that caries probably ispresent or developing in sections 322 on the maxillary central incisor324 and maxillary lateral incisor 325. The derived information isvisualized using a symbol 330 on the digital model of the segmentedtooth 327 as illustrated on FIG. 3C.

FIG. 3D shows symbols 330, 331 for the tooth condition derived for themaxillary central and lateral incisors projected onto the correspondingregions of a digital dental chart 332 like the one described in FIG. 1 .The thereby populated digital dental chart can be stored and examinede.g. at the next visit at the dental clinic to determine what haschanged since the last visit.

FIG. 4 shows a schematic of a system according to an embodiment. Thesystem 440 comprises a computer device 441 comprising a computerreadable medium 442 and an electronic data processing device in the formof a microprocessor 443. The system further comprises a visual displayunit 444, and at least one access device and/or interface that allow theoperator to utilize the functionality of the computer system. The accessdevice and/or interface can include but is not limited to a keyboard,mouse, touch screen, stylus, joystick, light pen, trackball, voiceinteractive function, three-dimensional glove, solid three-dimensionalmouse ball, graphical user interface (GUI), display screen, printer, andother known input or output devices and interfaces. In FIG. 4 the accessdevices are a computer keyboard 445 and a computer mouse 446 forentering data and activating virtual buttons of a user interfacevisualized on the visual display unit 444. The visual display unit 444can e.g. be a computer screen. The computer device 441 is capable ofobtaining a digital 3D representation of the patient’s teeth anddiagnostic data which both can be stored in the computer readable medium442 and loaded to the microprocessor 443 for processing. The digital 3Drepresentation can be obtained from a 3D color scanner 450, such as theTRIOS 3 intra-oral scanner manufactured by 3Shape TRIOS A/S, which iscapable of recording both shape and color of the teeth.

The computer system provides for the execution of the method steps bywhich the acquired digital 3D representation can be manipulated, eitherautomatically or in response to operator commands. The computer may be ageneral purpose computer capable of running a wide variety of differentsoftware applications or a specialized device limited to particularfunctions. In some embodiments, the computer is a network or otherconfiguration of computing devices. The computer may include any type,number, form, or configuration of processors, system memory,computer-readable mediums, peripheral devices, and operating systems.

In one embodiment, the computer includes a personal computer (PC), whichmay be in the form of a desktop, laptop, tablet PC, or other known formsof personal computers. Diagnostic data can be recording using differenttypes of diagnostic devices 451, such as an Infrared scanner and a CBCTscanner for recording infrared and data CBCT data, respectively. Therecorded data are loaded into the computer readable medium 442 andanalyzed using the microprocessor 443 to derive the tooth conditioninformation for the patient’s teeth.

A digital dental chart containing previously recorded data for thepatient is stored on the computer readable medium 442 from where it canbe loaded into the microprocessor 443 and visualized on the visualdisplay 444 unit such that the dentist can recall the dental history ofthe patient.

The system 441 is configured for allowing an operator to arrange thedigital 3D representation and the diagnostic data according to thespatial arrangement which best reflects to anatomical correctarrangement. This is relevant when the spatial correlation between thedigital 3D representation and the diagnostic data is needed but notknown. This can e.g. be the case when the diagnostic data are CBCT datawhich has been recorded independently of the digital 3D representation.The digital 3D representation and the diagnostic data can be movedrelative to each other in three dimensions using e.g. a computer mouseto drag or rotate visualizations of the digital 3D representation andthe diagnostic data on the visual display unit 444. When the operator issatisfied with the relative arrangement he activates a virtual pushbutton in the user interface and the spatial relationship is stored inthe computer readable medium 442.

Stored on the computer readable medium 442 is also computer programproduct having instructions for analyzing the diagnostic data to derivetooth condition information for the patient’s teeth.

The computer readable medium 442 further stores a computer programproduct for the segmenting of teeth from the digital 3D representationand the identification of the individual teeth. When applied to thedigital 3D representation the result is digital models of the individualteeth where the corresponding teeth numbers are known. These digitalmodels of the individual teeth can be stored together with the digitaldental chart in the patient’s electronic journal on the computerreadable medium 442 and be re-used at the next visit for theidentification of individual teeth in a digital 3D representationrecorded at the next visit.

When the spatial correlation between the digital 3D representation andthe diagnostic data is know it is also known which tooth or teeth agiven tooth condition information is derived for. Once the toothcondition information is derived it can thus be projected onto thedigital dental chart visualized in the visual display unit 444. Therebythe dentist will have a useful tool for evaluating the patient’s dentalsituation and to determine which treatments can be applied to correctfor any problems.

FIG. 5 shows a schematic of a digital work space of a digitalenvironment according to an embodiment.

In a first part 557 of the digital workspace 555 a segmented tooth 527from a digital 3D representation is illustrated. Tooth conditioninformation 530 has been derived from obtained diagnostic data and isvisualized on the segmented tooth. A digital dental chart 560 is alsoseen in the first part 557 of the digital workspace 555. When theoperator has confirmed the derived tooth condition information a symbolfor the information can be projected onto the digital dental chart 560by activating the virtual push button 561. The virtual push button cane.g. be activated using a computer mouse button. The same mouse buttoncan also be used for adjusting the position of the symbol on the regionof the digital dental chart representing the tooth if the operatordesires to do so.

The second part 558 of the digital workspace comprises data enteringsections 562, 563 e.g. for entering the dentist’s comments relating tothe patient’s dental situation, for selecting which diagnostic data toanalyze and for choosing the digital dental chart which the toothcondition information is to be recorded on.

The digital workspace can be visualized on a visual display unit, suchas a computer screen being part of a system configured for implementingthe disclosed method.

The digital environment and workspace illustrated in FIG. 5 comprisesone or more digital tools which can be displayed in the digitalworkspace. These digital tools allowing the operator to interact withthe digital environment e.g. by entering data and to be part in at leastone of the steps of identifying, segmenting, deriving and correlating.In FIG. 5 one of these tools is embodied as the virtual push button 561.

When activated the virtual push button causes the execution ofinstructions for populating the digital dental chart with the derivedtooth condition information. Digital tools for segmenting andidentifying the individual teeth from the digital 3D representation canbe embodied by instructions of a computer program product allowing foran automatic segmentation and identification of the teeth.

Although some embodiments have been described and shown in detail, theinvention is not restricted to them, but may also be embodied in otherways within the scope of the subject matter defined in the followingclaims. In particular, it is to be understood that other embodiments maybe utilized and structural and functional modifications may be madewithout departing from the scope of the present invention.

In device claims enumerating several means, several of these means canbe embodied by one and the same item of hardware. The mere fact thatcertain measures are recited in mutually different dependent claims ordescribed in different embodiments does not indicate that a combinationof these measures cannot be used to advantage.

A claim may refer to any of the preceding claims, and “any” isunderstood to mean “any one or more” of the preceding claims.

It should be emphasized that the term “comprises/comprising” when usedin this specification is taken to specify the presence of statedfeatures, integers, steps or components but does not preclude thepresence or addition of one or more other features, integers, steps,components or groups thereof.

The features of the method described above and in the following may beimplemented in software and carried out on a data processing system orother processing means caused by the execution of computer-executableinstructions. The instructions may be program code means loaded in amemory, such as a RAM, from a storage medium or from another computervia a computer network. Alternatively, the described features may beimplemented by hardwired circuitry instead of software or in combinationwith software.

What is claimed is:
 1. A method for deriving tooth condition informationfor a patient’s teeth, wherein the method comprises: obtaining a digital3D representation of the patient’s teeth; identifying individual teethin the digital 3D representation; segmenting the individual teeth fromthe digital 3D representation; obtaining diagnostic data for one or moreof the teeth; deriving tooth condition information from the diagnosticdata; and correlating the derived tooth information with the individualteeth.